Reduced Interhemispheric Functional Connectivity in the Motor Cortex during Rest in Limb-Onset Amyotrophic Lateral Sclerosis - PubMed (original) (raw)

Reduced Interhemispheric Functional Connectivity in the Motor Cortex during Rest in Limb-Onset Amyotrophic Lateral Sclerosis

Laura M Jelsone-Swain et al. Front Syst Neurosci. 2010.

Abstract

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder of motor neurons that leads to paralysis and eventually death. There is evidence that atrophy occurs in the primary motor cortex (M1), but it is unclear how the disease affects the intrinsic connectivity of this structure. Thus, the goal of this study was to examine interhemispheric coupling of low frequency blood-oxygen-level dependent (BOLD) signal fluctuations in M1 using functional connectivity magnetic resonance imaging during rest. Because disease progression is rapid, high-functioning patients were recruited to assess neural changes in the relatively early stages of ALS. Twenty patients with limb-onset ALS participated in this study. A parceling technique was employed to segment both precentral gyri into multiple regions of interest (ROI), thus increasing sensitivity to detect changes that exist along discretely localized regions of the motor cortex. We report an overall systemic decrease in functional connectivity between right and left motor cortices in patients with limb-onset ALS. Additionally, we observed a pronounced disconnection between dorsal ROI pairs in the ALS group compared to the healthy control group. Furthermore, measures of limb functioning correlated with the connectivity data from dorsal ROI pairs in the ALS group, suggesting a symptomatic relationship with interhemispheric M1 connectivity.

Keywords: ALS; fcMRI; primary motor cortex; resting-state.

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Figures

Figure 1

Figure 1

Group average precentral gyrus masks in left and right hemispheres.

Figure 2

Figure 2

Masks applied to correlation-grams after initial analysis of all ROI pairs. (A) diagonal-only mask; (B) ventral mask; (C) dorsal mask.

Figure 3

Figure 3

Correlation-gram displaying all ROI Pearson's _r_-correlation coefficient means for the healthy control group. Coordinates along the axes of this map represent ROIs in left and right hemispheres, moving from ventral to dorsal locations.

Figure 4

Figure 4

Correlation-gram displaying all ROI Pearson's _r_-correlation coefficient means for the ALS patient group. Coordinates along the axes of this map represent ROIs in left and right hemispheres, moving from ventral to dorsal locations.

Figure 5

Figure 5

Scatter-plot showing the correlation between average dorsal ROI interhemispheric connectivity per individual and hand strength disparity, across groups. Only results from the ALS group are significantly (inversely) correlated.

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References

    1. Agosta F., Chio A., Cosottini M., De Stefano N., Falini A., Mascalchi M., Rocca M. A., Silani V., Tedeschi G., Filippi M. (2010). The present and future of neuroimaging in amyotrophic lateral sclerosis. Am. J. Radiol. 31, 1769–1777 - PMC - PubMed
    1. Bartels C., Mertens N., Hofer S., Merboldt K. D., Dietrich J., Frahm J., Ehrenreich H. (2008). Callosal dysfunction in amytrophic lateral sclerosis correlates with diffusion tensor imaging of the central motor system. Neuromuscul. Disord. 18, 398–407 - PubMed
    1. Biswal B. B., Van Kylen J., Hyde J. S. (1997). Simultaneous assessment of flow and BOLD signals in resting-state functional connectivity maps. NMR Biomed. 10, 165–17010.1002/(SICI)1099-1492(199706/08)10:4/5<165::AID-NBM454>3.0.CO;2-7 - DOI - PubMed
    1. Biswal B. B., Yetkin F. Z., Haughton V. M., Hyde J. S. (1995). Functional connectivity in the motor cortex of resting human brain using echo-planar MRI. Magn. Reson. Med. 34, 537–541 - PubMed
    1. Brownell B., Oppenheimer D. R., Hughes J. T. (1970). The central nervous system in motor neurone disease. J. Neurol. Neurosurg. Psychiatr. 33, 338–357 - PMC - PubMed

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